Generating congruous metadata for multimedia

ABSTRACT

A method of generating congruous metadata is provided. The method includes receiving a similarity measure between at least two multimedia objects. Each multimedia object has associated metadata. If the at least two multimedia objects are similar based on the similarity measure and a similarity threshold, the associated metadata of each of the multimedia objects are compared. Then, based on the comparison of the associated metadata of each of the at least two multimedia objects, the method further includes generating congruous metadata. Metadata may be tags, for example.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority fromco-pending U.S. patent application Ser. No. 12/042,306, filed Mar. 4,2008, entitled GENERATING CONGRUOUS METADATA FOR MULTIMEDIA, thecontents of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Digital photography users often use online photo-sharing sites to uploadtheir digital photos to easily share with friends and family. Users ofthese photo sharing sites often generate metadata, such as tags, todescribe the images that they have uploaded to the online photosharingsite. Metadata, or data about an object, may include a location or time,for example. This type of user-generated content can be utilized toaccess other content on the Internet.

However, metadata, like tags, are indiscriminately applied, and may notaccurately describe an image. For example, all photos from a user's tripto Japan during Christmas might be labeled “japan,” but also“Christmas”. Similarly, images that are part of a family's Christmascelebration, including an annual trip to the beach are also labeled“Christmas.” These images, even with a common tag, have a good chance ofnot being meaningful to other users. Therefore, these tags are notreliable and congruous with the expectations of the large population ofInternet users. If these tags are utilized by other users or services togenerate content, the results may not be accurate.

Previously, the ESP Game was developed to test whether two differentusers would label and image with the same word. The ESP Game allows fortwo users to generate metadata for one image. This game puts an image infront of two users and then awards points to players when two playerssuggest the same tag to describe an image. For example, it is likelythat two users shown an image of the Augsburg church will both label theimage with “church.” The idea of the ESP Game is that if both users usethe same descriptive word for the metadata, then there is a highreliability that the metadata the two users used applies to the image.

However, it is highly unlikely that two random users from the Internetwill know the location of the church and, thus, will not label thechurch with “Augsburg.” The way these tags are generated in a multi-usergame is not useful in returning images that are representative of theAugsburg church. It is more likely that the user, who is the owner ofthe image of the Augsburg church, would provide a more accuratedescription of the image.

Therefore, a method for generating congruous metadata that accuratelydescribes similar images is desired.

BRIEF SUMMARY OF THE INVENTION

In accordance with embodiments of the present invention, a method ofgenerating congruous metadata is provided. The method includes receivinga similarity measure between at least two multimedia objects. Eachmultimedia object has associated metadata. If the at least twomultimedia objects are similar based on the similarity measure and asimilarity threshold, the associated metadata of each of the multimediaobjects are compared. Then, based on the comparison of the associatedmetadata of each of the at least two multimedia objects, the methodfurther includes generating congruous metadata. Metadata may be tags, orestimates of image contents, for example.

In other embodiments of the present invention, a computer-readablemedium encoded with computer instructions for generating congruousmetadata is provided. The instructions include receiving a similaritymeasure between at least two multimedia objects. Each multimedia objecthas associated metadata. The instructions further include comparing theassociated metadata of each of the at least two multimedia objects, ifthe at least two multimedia objects are similar based on the similaritymeasure and a similarity threshold. Then, based on the comparison of theassociated metadata of each of the at least two multimedia objects, theinstructions include generating congruous metadata.

In other embodiments of the present invention, a system for generatingcongruous metadata is provided. The apparatus includes logic fordetermining a similarity measure between at least two multimediaobjects. Each of the at least two multimedia objects has associatedmetadata. Logic for comparing the associated metadata of each of the atleast two multimedia objects, if the at least two multimedia objects aresimilar, based on the similarity measure and a similarity threshold, isalso included in the apparatus. Furthermore, the apparatus includeslogic for generating congruous metadata based on the comparison of theassociated metadata of each of the at least two multimedia objects.

Other features and aspects of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings which illustrate, by way of example, the featuresin accordance with embodiments of the invention. The summary is notintended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a flowchart of a method for generating congruousmetadata for multimedia objects according to embodiments of theinvention;

FIG. 2 illustrates an example of two images that may be used to generatecongruous metadata according to embodiments of the invention;

FIG. 3 illustrates a flowchart of an example according to embodiments ofthe invention;

FIG. 4 illustrates a system for generating congruous metadata accordingto embodiments of the invention; and

FIG. 5 illustrates a block diagram of a computing system according toembodiments of the invention.

In the following description, reference is made to the accompanyingdrawings which form a part thereof, and which illustrate severalembodiments of the present invention. It is understood that otherembodiments may be utilized and structural and operational changes maybe made without departing from the scope of the present invention. Theuse of the same reference symbols in different drawings indicatessimilar or identical items.

DETAILED DESCRIPTION OF THE INVENTION

The following description is presented to enable any person of ordinaryskill in the art to make and use the invention. Descriptions of specificmaterials, techniques, and applications are provided only as examples.Various modifications to the examples described herein will be readilyapparent to those of ordinary skill in the art, and the generalprinciples defined herein may be applied to other examples andapplications without departing from the spirit and scope of theinvention. Thus, the present invention is not intended to be limited tothe examples described and shown.

Currently, there are a huge number of images online. With so many usersuploading these images and independently providing image tags, each useris an expert on the particular images that belong to them. Similarly,other multimedia, such as videos and audio files, are tagged by users.

Therefore, by utilizing the metadata that are already associated with animage in a database according to embodiments of the invention, there maybe some metadata associated with a group of images that can be labeledas congruous. Metadata may be image tags, location, time, and facialidentification, for example. Congruous metadata can be utilized forimage searching in order to find desired images. Moreover, metadatalabeled congruous can be used for automatic image classification,learning tag models, and other semantic data about accessible multimediadata.

FIG. 1 illustrates a flowchart of a method for generating congruousmetadata for multimedia objects according to embodiments of theinvention. The input to method 100 may be a large set of multimediaobjects with associated metadata. Multimedia objects may be images,audio, or video, for example. The associated metadata may be tagannotations. Tag annotations are typically added by a user as a labelfor the multimedia objects. At least two multimedia objects 104 and 106are selected from the large set of multimedia objects. In other wordsmore than two multimedia objects may be selected.

In decision 108, a similarity algorithm is applied to multimedia object1 104 and multimedia object 2 106 to determine a similarity measure. Thesimilarity measure indicates if multimedia object 1 104 and multimediaobject 2 106 are similar or dissimilar. Similarity may be determined bycomparing the similarity measure with a similarity threshold. Asimilarity threshold may be predetermined. The similarity threshold mayalso be adjusted to be more or less restrictive. For example, in thecase the multimedia objects are images, if the similarity threshold ismore restrictive, the similarity algorithm will determine images aresimilar if features of the image are very similar. In some embodiments,the similarity threshold may be high, or that the degree of similarityis higher, since there may be no user actually verifying that the tagsapply to a particular multimedia object.

In some embodiments, a similarity measure determines the most similarset of multimedia objects of one multimedia objects. For example, for afirst multimedia object, a first set of similar multimedia objects maybe determined from a similarity measure. Similarly, a second set ofsimilar multimedia objects may be determined for a second multimediaobject. If the first multimedia object is included in the second set ofsimilar multimedia objects, and the second multimedia object is includedin the first set of similar multimedia objects, it can be determinedthat the first and second multimedia objects are similar.

There are many well-known similarity algorithms. A similarity measuremay be determined in an automated fashion, so that no user interventionis required. A color histogram, a Probabilistic Latent Semantic Analysis(PLSA), a K-nearest neighbor algorithm in pixel space, or a localinvariant features algorithm, such as a Scale-Invariant FeatureTransform (SIFT) algorithm can be used to determine a similaritymeasure, for example.

A common framework is to first represent the two instances, e.g., twoimages, as vectors and then use a metric to compute their pairwisedistance. Representing the two instances as vectors and computingpairwise distance may be both determined in an automated fashion, sothat no user intervention is required.

There are many ways to put an instance into vector representation.Images can be represented as color histograms, pixels in various colorspaces or more elaborate feature representations that are extracted withspecialized algorithms. Algorithms for feature extraction include LatentSemantic Analysis (LSA), Probabilistic Latent Semantic Analysis (PLSA),Latent Dirichlet Allocation, Scale-Invariant Feature Transform (SIFT),and Geometric Blur, for example. Using an like SIFT, for example,important points in an image are determined and using these points candetermine the degree of similarity between the two images.

The distance metric can be a standard Euclidean metric (commonly L1, L2or the Mahalanobis Metric) or an especially learned metric. Especiallylearned metrics may include Large Margin Nearest Neighbor (LMNN),Invariant Mappings based on Convolutional Neural Networks, and LinearDiscriminent Analysis, for example.

Similar to image similarity algorithms, multimedia, such as audio andvideo, may be compared with similarity algorithms. However, determiningvideo and audio similarity is difficult because the time-course of thesignal can be altered and it can still convey the same message.

For example, but not limited to, video similarity can be judged by firstcreating a “video mosaic”. In a video mosaic, a video shot is summarizedby creating a single wide-view image showing everything that the camerasees as it pans over the scene. This may be done by aligning portions ofeach new image with the existing mosaic, thus extending the mosaic tocover larger and larger regions of the original scene. In this way, avideo-similarity problem because similar to an image-similarity problem.

Similarly to video, audio signals have a similar problem in that it is asignal over time. However, unlike video, there is no easy staticrepresentation that shows the entire signal. For example, instead bygenerating cover-song detection to find short snippets—shingles—that aresimilar in the query signal and the database can determine audiosimilarity. Using locality-sensitive hashing techniques this audiosimilarity problem can be solved in highly efficient manner.

The similarity of two audio signals can be measured by converting theaudio waveforms into a feature space such as linear-predicted coding(LPC) or MFCC (mel-frequency cepstral coefficients). The MFCCcoefficients represent the broad spectral shape of the audio signal overshort (i.e. 20 ms) windows of the signal. By calculating the sum overtime of the Euclidean distance between two time-varying signalrepresentations, one can make an elementary distance calculation. Abetter measure of the similarity of two signals is found by allowing forsmall changes in the speed of one or the other signals. This can be doneusing an algorithm known as dynamic-time warping.

With reference to FIG. 1 , if it is determined that multimedia object 1104 and multimedia object 2 106 are not similar by the similarityalgorithm, then two other multimedia objects are selected from the groupto compare.

However, if it is determined that multimedia object 1 104 and multimediaobject 2 106 are similar by the similarity measure resulting from thesimilarity algorithm, then the associated metadata 110 of multimediaobject 1 and the associated metadata 112 of multimedia object 2 arecompared to find common metadata of the two multimedia objects. Themetadata may be tag annotations. The metadata may include time orlocation indications, for example.

FIG. 2 illustrates examples of two images that may be selected todetermine any congruous metadata. Image 200 and image 210 both showimages of the Golden Gate Bridge in San Francisco. However, theassociated metadata, or tags, are not all shared by both images.

As illustrated in the flowchart of FIG. 3 , it is determined there iscongruous metadata associated with images 200 and 210. The two images200 and 210 are input for determining if the two images are similar 304.

The common metadata is determined to be congruous metadata in that themetadata accurately describes both images. The congruous metadata may bestored in a database, or flagged. In this way, the data vetted to becongruous may be available to be utilized in other functions.

FIG. 4 illustrates a system for generating congruous metadata accordingto embodiments of the invention. The system 400 may include a searchserver 404 and a media server 408. A user 410 is provided congruousmetadata from search server 404, or media server 408. A set of imagesthat are to be used to generate congruous metadata may come from storedimages from a media server 408, such as a digital photo sharing website.For example, a media server 408 may be a website such as Flickr. Othertypes of multimedia may be stored in the media server 408. The imagesimilarity measure may be determined at a search server 404 or mediaserver 408. The server 404 or media server 408 may also determine if theimages are similar based on the similarity measure and a similaritythreshold. Further, the server 404 or media server 408 may also comparethe associated metadata of each the images for common associatedmetadata that can be determined as congruous metadata.

The search server 404 may also be associated with a database 410. Thedatabase 410 may store, among other things, congruous metadataassociated with a multimedia object. Similarly, a media server may beassociated with a database 406. The database 406 may store, among otherthings, congruous metadata associated with a multimedia object. Database410 and database 406 may also store flags associated with the congruousmetadata.

While aspects of the invention, including the above described systemsand methods, are described in terms of particular embodiments andillustrative figures, those of ordinary skill in the art will recognizethat the invention is not limited to the embodiments or figuresdescribed. Those skilled in the art will recognize that the operationsof the various embodiments may be implemented using hardware, software,firmware, or combinations thereof, as appropriate. For example, someprocesses can be carried out using processors or other digital circuitryunder the control of software, firmware, or hard-wired logic. (The term“logic” herein refers to fixed hardware, programmable logic, and/or anappropriate combination thereof, as would be recognized by one skilledin the art to carry out the recited functions.) Software and firmwarecan be stored on computer-readable media. Some other processes can beimplemented using analog circuitry, as is well known to one of ordinaryskill in the art. Additionally, memory or other storage, as well ascommunication components, may be employed in embodiments of theinvention.

FIG. 5 illustrates an exemplary computing system 500 that may beemployed to implement processing functionality for various aspects ofthe invention (e.g., as a server device, client device, database,combinations thereof, and so on). Those skilled in the relevant art willalso recognize how to implement the invention using other computersystems or architectures. Computing system 500 may represent, forexample, a desktop, mainframe, server, client, or any other type ofspecial or general purpose computing device as may be desirable orappropriate for a given application or environment. Computing system 500can include one or more processors, such as a processor 504. Processor504 can be implemented using a general or special purpose processingengine such as, for example, a microprocessor, microcontroller or othercontrol logic. In this example, processor 504 is connected to a bus 502or other communication medium.

Computing system 500 can also include a main memory 508, for examplerandom access memory (RAM) or other dynamic memory, for storinginformation and instructions to be executed by processor 504. Mainmemory 508 also may be used for storing temporary variables or otherintermediate information during execution of instructions to be executedby processor 504. Computing system 500 may likewise include a read onlymemory (“ROM”) or other static storage device coupled to bus 502 forstoring static information and instructions for processor 504.

The computing system 500 may also include information storage mechanism510, which may include, for example, a media drive 512 and a removablestorage interface 520. The media drive 512 may include a drive or othermechanism to support fixed or removable storage media, such as a harddisk drive, a floppy disk drive, a magnetic tape drive, an optical diskdrive, a CD or DVD drive (R or RW), or other removable or fixed mediadrive. Storage media 518 may include, for example, a hard disk, floppydisk, magnetic tape, optical disk, CD or DVD, or other fixed orremovable medium that is read by and written to by media drive 514. Asthese examples illustrate, the storage media 518 may include acomputer-readable storage medium having stored therein particularcomputer software or data.

In alternative embodiments, information storage mechanism 510 mayinclude other similar instrumentalities for allowing computer programsor other instructions or data to be loaded into computing system 500.Such instrumentalities may include, for example, a removable storageunit 522 and an interface 520, such as a program cartridge and cartridgeinterface, a removable memory (for example, a flash memory or otherremovable memory module) and memory slot, and other removable storageunits 522 and interfaces 520 that allow software and data to betransferred from the removable storage unit 518 to computing system 500.

Computing system 500 can also include a communications interface 524.Communications interface 524 can be used to allow software and data tobe transferred between computing system 500 and external devices.Examples of communications interface 424 can include a modem, a networkinterface (such as an Ethernet or other NIC card), a communications port(such as for example, a USB port), a PCMCIA slot and card, etc. Softwareand data transferred via communications interface 524 are in the form ofsignals which can be electronic, electromagnetic, optical, or othersignals capable of being received by communications interface 524. Thesesignals are provided to communications interface 524 via a channel 528.This channel 528 may carry signals and may be implemented using awireless medium, wire or cable, fiber optics, or other communicationsmedium. Some examples of a channel include a phone line, a cellularphone link, an RF link, a network interface, a local or wide areanetwork, and other communications channels.

In this document, the terms “computer program product” and“computer-readable medium” may be used generally to refer to media suchas, for example, memory 508, storage device 518, storage unit 522, orsignal(s) on channel 528. These and other forms of computer-readablemedia may be involved in providing one or more sequences of one or moreinstructions to processor 504 for execution. Such instructions,generally referred to as “computer program code” (which may be groupedin the form of computer programs or other groupings), when executed,enable the computing system 500 to perform features or functions ofembodiments of the present invention.

In an embodiment where the elements are implemented using software, thesoftware may be stored in a computer-readable medium and loaded intocomputing system 500 using, for example, removable storage drive 514,drive 512 or communications interface 524. The control logic (in thisexample, software instructions or computer program code), when executedby the processor 504, causes the processor 504 to perform the functionsof the invention as described herein.

It will be appreciated that, for clarity purposes, the above descriptionhas described embodiments of the invention with reference to differentfunctional units and processors. However, it will be apparent that anysuitable distribution of functionality between different functionalunits, processors or domains may be used without detracting from theinvention. For example, functionality illustrated to be performed byseparate processors or controllers may be performed by the sameprocessor or controller. Hence, references to specific functional unitsare only to be seen as references to suitable means for providing thedescribed functionality, rather than indicative of a strict logical orphysical structure or organization.

Although the present invention has been described in connection withsome embodiments, it is not intended to be limited to the specific formset forth herein. Rather, the scope of the present invention is limitedonly by the claims. Additionally, although a feature may appear to bedescribed in connection with particular embodiments, one skilled in theart would recognize that various features of the described embodimentsmay be combined in accordance with the invention. Moreover, aspects ofthe invention describe in connection with an embodiment may stand aloneas an invention.

Furthermore, although individually listed, a plurality of means,elements or method steps may be implemented by, for example, a singleunit or processor. Additionally, although individual features may beincluded in different claims, these may possibly be advantageouslycombined, and the inclusion in different claims does not imply that acombination of features is not feasible and/or advantageous. Also, theinclusion of a feature in one category of claims does not imply alimitation to this category, but rather the feature may be equallyapplicable to other claim categories, as appropriate.

Moreover, it will be appreciated that various modifications andalterations may be made by those skilled in the art without departingfrom the spirit and scope of the invention. The invention is not to belimited by the foregoing illustrative details, but is to be definedaccording to the claims.

What is claimed is:
 1. A method comprising: determining, by a computingdevice of a multimedia system, a similarity between content of a firstcontent item and content of a second content item, the determiningcomprising analyzing digital data of the first and second content itemsto determine the similarity; using, by the computing device, informationindicating an absence of user verification of computer-generatedcongruous metadata to make a determination to dynamically adjust anadjustable similarity threshold configured for adjustment between beingmore or less restrictive; adjusting, by the computing device, inresponse to the determination, the adjustable similarity threshold to bemore restrictive requiring a higher degree of similarity between thefirst and second content items in the absence of user verification ofthe computer-generated congruous metadata; determining, by the computingdevice, that the similarity determined for the first and second contentitems satisfies the adjustable similarity threshold; responsive todetermining that the similarity satisfies the adjustable similaritythreshold, comparing, by the computing device, a first set of metadataassociated with the first content item with a second set of metadataassociated with the second content item, the comparing comprisingidentifying metadata found in both the first and second sets ofmetadata; automatically generating, by the computing device, thecongruous metadata comprising the identified metadata found in both thefirst and second sets of metadata; and in response to a retrievalrequest comprising at least some of the congruous metadata as selectioncriteria, retrieving, via the computing device and from a data store, atleast one of the first and second content items.
 2. The method of claim1, further comprising: storing, by the computing device and in the datastore, the congruous metadata, the storing comprising associating thecongruous metadata with both the first and second content items.
 3. Themethod of claim 1, determining a similarity between content of a firstcontent item and content of a second content item further comprising:determining, for the first content item, a first set of content itemssimilar to the first content item; determining, for the second contentitem, a second set of content items similar to the second content item;determining that the similarity of the first and second content itemssatisfies the similarity threshold if the first content item is includedin the second set of content items similar to the second content itemand the second content item is included in the first set of contentitems similar to the first content item.
 4. The method of claim 3,further comprising: determining the first set of content itemscomprising using a similarity measure associated with each content itemof the first set, the similarity measure associated with a content itemof the first set indicating the similarity of the content item to thefirst content item; and determining the second set of content itemscomprising using a similarity measure associated with each content itemof the second set, the similarity measure associated with a content itemof the second set indicating the similarity of the content item to thesecond content item.
 5. The method of claim 1, determining a similaritybetween content of a first content item and content of a second contentitem further comprising: determining a representation of the firstcontent item using the content of the first content item; determining arepresentation of the second content item using the content of thesecond content item; and determining a difference between therepresentation of the first content item and the representation of thesecond content item.
 6. The method of claim 5, the representation of thefirst content item and the representation of the second content itemcomprising a vector representation.
 7. The method of claim 5, therepresentation of the first content item and the representation of thesecond content item comprising a video mosaic representation.
 8. Themethod of claim 5, the representation of the first content item and therepresentation of the second content item comprising an audio waveformsignal.
 9. The method of claim 1, the identified metadata found in boththe first and second sets of metadata used in automatically generatingthe congruous metadata comprising user-generated metadata found in boththe first and second sets of metadata.
 10. A non-transitorycomputer-readable storage medium tangibly encoded withcomputer-executable instructions that when executed by a processorassociated with a computing device perform a method comprising:determining a similarity between content of a first content item andcontent of a second content item, the determining comprising analyzingdigital data of the first and second content items to determine thesimilarity; using information indicating an absence of user verificationof computer-generated congruous metadata to make a determination todynamically adjust an adjustable similarity threshold configured foradjustment between being more or less restrictive; adjust, in responseto the determination, the adjustable similarity threshold to be morerestrictive requiring a higher degree of similarity between the firstand second content items in the absence of user verification of thecomputer-generated congruous metadata; determining that the similaritydetermined for the first and second content items satisfies theadjustable similarity threshold; responsive to determining thesimilarity satisfies the adjustable similarity threshold, comparing afirst set of metadata associated with the first content item with asecond set of metadata associated with the second content item, thecomparing comprising identifying metadata found in both the first andsecond sets of metadata; automatically generating the congruous metadatausing the identified metadata found in both the first and second sets ofmetadata; and in response to a retrieval request comprising at leastsome of the congruous metadata as selection criteria, retrieving, from adata store, at least one of the first and second contents.
 11. Thenon-transitory computer-readable storage medium of claim 10, determininga similarity between content of a first content item and content of asecond content item further comprising: determining, for the firstcontent item, a first set of content items similar to the first contentitem; determining, for the second content item, a second set of contentitems similar to the second content item; determining that thesimilarity of the first and second content items satisfies thesimilarity threshold if the first content item is included in the secondset of content items similar to the second content item and the secondcontent item is included in the first set of content items similar tothe first content item.
 12. The non-transitory computer-readable storagemedium of claim 11, further comprising: determining the first set ofcontent items comprising using a similarity measure associated with eachcontent item of the first set, the similarity measure associated with acontent item of the first set indicating the similarity of the contentitem to the first content item; and determining the second set ofcontent items comprising using a similarity measure associated with eachcontent item of the second set, the similarity measure associated with acontent item of the second set indicating the similarity of the contentitem to the second content item.
 13. The non-transitorycomputer-readable storage medium of claim 10, determining a similaritybetween content of a first content item and content of a second contentitem further comprising: determining a representation of the firstcontent item using the content of the first content item; determining arepresentation of the second content item using the content of thesecond content item; and determining a difference between therepresentation of the first content item and the representation of thesecond content item.
 14. The non-transitory computer-readable storagemedium of claim 13, the first and second content items comprising imagecontent and the representation of the first content item and therepresentation of the second content item comprising a vectorrepresentation.
 15. The non-transitory computer-readable storage mediumof claim 14, the first and second content items comprising video contentand the representation of the first content item and the representationof the second content item comprising a video mosaic representation. 16.The non-transitory computer-readable storage medium of claim 14, thefirst and second content items comprising audio content and therepresentation of the first content item and the representation of thesecond content item comprising an audio waveform signal.
 17. Thenon-transitory computer-readable storage medium of claim 14, theidentified metadata found in both the first and second sets of metadataused in automatically generating the congruous metadata comprisinguser-generated metadata found in both the first and second sets ofmetadata.
 18. A computing device comprising: a processor; and anon-transitory storage medium for tangibly storing thereon program logicfor execution by the processor, the program logic comprising:determining logic executed by the processor for determining a similaritybetween content of a first content item and content of a second contentitem, the determining comprising analyzing digital data of the first andsecond content items to determine the similarity; using logic executedby the processor for using information indicating an absence of userverification of computer-generated congruous metadata to make andetermination to dynamically adjust an adjustable similarity thresholdconfigured for adjustment between being more or less restrictive;adjusting logic executed by the processor for adjust, in response to thedetermination, the adjustable similarity threshold to be morerestrictive requiring a higher degree of similarity between the firstand second content items in the absence of user verification of thecomputer-generated congruous metadata; determining logic executed by theprocessor for determining that the similarity determined for the firstand second content items satisfies the adjustable similarity threshold;comparing logic executed by the processor for, responsive to determiningthe similarity satisfies the adjustable similarity threshold, comparinga first set of metadata associated with the first content item with asecond set of metadata associated with the second content item, thecomparing comprising identifying metadata found in both the first andsecond sets of metadata; generating logic executed by the processor forautomatically generating the congruous metadata using the identifiedmetadata found in both the first and second sets of metadata; and inresponse to a retrieval request comprising at least some of thecongruous metadata as selection criteria, retrieving, from a data store,at least one of the first and second contents.